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The Nokia 3310 wasn't actually indestructible, but it was built like a brick. Almost impossible to break in day-to-day use, it became famous for its sturdiness, a reputation later echoed by rugged Nokia-branded phones. So why was the Nokia 3310 so hard to break? It comes down to the era it was built in, and the design it ended up with.

Today's phones are usually weakest at the screen, and it's common for a smartphone to crack right where you need it most. Even with tougher glass than ever, iPhone 13 drop tests show what it takes for the glass to crack . The Nokia 3310's tiny 84 × 48-pixel monochrome display, on the other hand, sat behind a thick plastic window rather than exposed glass. Its compact "candy bar" shape and thick outer casing also made it hard to bend. A single rubber keypad sitting over membrane switches meant fewer mechanical parts that could fall.…